Currently, LTE (Long Term Evolution)-Advanced, which is a specification of a next generation radio communication, is developed and specified in 3GPP (3rd Generation Partnership Project), which is a standardization project of a mobile communication system.
LTE-Advanced supports a relay station, which relays between abase station and a user equipment in layer 3 level. The relay station has a user equipment function unit, which establishes a connection with the base station, and a base station function unit, which establishes a connection with the user equipment (e.g. referring NON-PATENT DOCUMENT 1). “Connection” is specified in layer 3 level, and is referred to as RRC (Radio Resource Control) Connection.
Moreover, a mobile type relay station is mentioned as a candidate for the next expansion function of LTE-Advanced (e.g. referring NON-PATENT DOCUMENT 2).